Rework foreground color and remove outdated methods

src/Core/src/Platform/Windows/ActivityIndicatorExtensions.cs

@@ -2,6 +2,7 @@
 using Microsoft.Maui.Graphics;
 using Microsoft.Maui.Primitives;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Media;
 
 namespace Microsoft.Maui.Platform
 {
@@ -11,26 +12,46 @@ public static void UpdateIsRunning(this ProgressRing platformActivityIndicator,
 		{
 			platformActivityIndicator.IsActive = virtualView.IsRunning;
 		}
+
 		public static void UpdateColor(this ProgressRing platformActivityIndicator, IActivityIndicator activityIndicator)
 		{
 			platformActivityIndicator.UpdateColor(activityIndicator, null);
 		}
 
 		public static void UpdateColor(this ProgressRing platformActivityIndicator, IActivityIndicator activityIndicator, object? foregroundDefault)
 		{
-			Color color = activityIndicator.Color;
+			var color = activityIndicator.Color;
+			Brush? brush = null;
 
 			if (color.IsDefault())
 			{
-				if (foregroundDefault != null)
-					platformActivityIndicator.RestoreForegroundCache(foregroundDefault);
+				if(foregroundDefault is Brush defaultBrush)
+					brush = defaultBrush;
+			}
+			else
+			{
+				brush = color.ToPlatform();
+			}
+
+			if (brush is null)
+			{
+				platformActivityIndicator.Resources.RemoveKeys(ProgressRingForegroundResourceKeys);
+				platformActivityIndicator.ClearValue(ProgressRing.ForegroundProperty);
 			}
 			else
 			{
-				platformActivityIndicator.Foreground = color.ToPlatform();
+				platformActivityIndicator.Resources.SetValueForAllKey(ProgressRingForegroundResourceKeys, brush);
+				platformActivityIndicator.Foreground = brush;
 			}
+
+			platformActivityIndicator.RefreshThemeResources();
 		}
 
+		static readonly string[] ProgressRingForegroundResourceKeys =
+		{
+			"ProgressRingForegroundThemeBrush"
+		};
+
 		public static void UpdateWidth(this ProgressRing platformActivityIndicator, IActivityIndicator activityIndicator)
 		{
 			if (Dimension.IsExplicitSet(activityIndicator.Width))

src/Core/src/Platform/Windows/FrameworkElementExtensions.cs

@@ -1,28 +1,18 @@
 #nullable enable
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.Linq;
-using System.Reflection;
-using System.Threading.Tasks;
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Media;
 using Windows.UI.ViewManagement;
-using WBinding = Microsoft.UI.Xaml.Data.Binding;
-using WBindingExpression = Microsoft.UI.Xaml.Data.BindingExpression;
-using WBrush = Microsoft.UI.Xaml.Media.Brush;
 using WPoint = Windows.Foundation.Point;
 
 namespace Microsoft.Maui.Platform
 {
 	internal static class FrameworkElementExtensions
 	{
-		static readonly Lazy<ConcurrentDictionary<Type, DependencyProperty>> ForegroundProperties =
-			new Lazy<ConcurrentDictionary<Type, DependencyProperty>>(() => new ConcurrentDictionary<Type, DependencyProperty>());
-
 		public static T? GetResource<T>(this FrameworkElement element, string key, T? def = default)
 		{
 			if (element.Resources.TryGetValue(key, out var resource))
@@ -31,59 +21,6 @@ internal static class FrameworkElementExtensions
 			return def;
 		}
 
-		public static WBrush GetForeground(this FrameworkElement element)
-		{
-			if (element == null)
-				throw new ArgumentNullException(nameof(element));
-
-			return (WBrush)element.GetValue(GetForegroundProperty(element));
-		}
-
-		public static WBinding? GetForegroundBinding(this FrameworkElement element)
-		{
-			WBindingExpression expr = element.GetBindingExpression(GetForegroundProperty(element));
-
-			if (expr == null)
-				return null;
-
-			return expr.ParentBinding;
-		}
-
-		public static object GetForegroundCache(this FrameworkElement element)
-		{
-			WBinding? binding = GetForegroundBinding(element);
-
-			if (binding != null)
-				return binding;
-
-			return GetForeground(element);
-		}
-
-		public static void RestoreForegroundCache(this FrameworkElement element, object cache)
-		{
-			var binding = cache as WBinding;
-			if (binding != null)
-				SetForeground(element, binding);
-			else
-				SetForeground(element, (WBrush)cache);
-		}
-
-		public static void SetForeground(this FrameworkElement element, WBrush foregroundBrush)
-		{
-			if (element == null)
-				throw new ArgumentNullException(nameof(element));
-
-			element.SetValue(GetForegroundProperty(element), foregroundBrush);
-		}
-
-		public static void SetForeground(this FrameworkElement element, WBinding binding)
-		{
-			if (element == null)
-				throw new ArgumentNullException(nameof(element));
-
-			element.SetBinding(GetForegroundProperty(element), binding);
-		}
-
 		public static void UpdateVerticalTextAlignment(this Control platformControl, ITextAlignment textAlignment)
 		{
 			platformControl.VerticalAlignment = textAlignment.VerticalTextAlignment.ToPlatformVerticalAlignment();
@@ -168,29 +105,6 @@ internal static void TryUpdateResource(this FrameworkElement element, object new
 			element?.RefreshThemeResources();
 		}
 
-		static DependencyProperty? GetForegroundProperty(FrameworkElement element)
-		{
-			if (element is Control)
-				return Control.ForegroundProperty;
-			if (element is TextBlock)
-				return TextBlock.ForegroundProperty;
-
-			Type type = element.GetType();
-
-			if (!ForegroundProperties.Value.TryGetValue(type, out var foregroundProperty))
-			{
-				if (ReflectionExtensions.GetFields(type).FirstOrDefault(f => f.Name == "ForegroundProperty") is not FieldInfo field)
-					throw new ArgumentException("type is not a Foregroundable type");
-
-				if (field.GetValue(null) is DependencyProperty property)
-					ForegroundProperties.Value.TryAdd(type, property);
-
-				return null;
-			}
-
-			return foregroundProperty;
-		}
-
 		internal static IEnumerable<T?> GetChildren<T>(this DependencyObject parent) where T : DependencyObject
 		{
 			int myChildrenCount = VisualTreeHelper.GetChildrenCount(parent);

src/Core/tests/DeviceTests/Handlers/ActivityIndicator/ActivityIndicatorHandlerTests.cs

@@ -36,5 +36,24 @@ public async Task BackgroundUpdatesCorrectly(uint color)
 
 			await ValidateHasColor(activityIndicator, expected, () => activityIndicator.Background = new SolidPaintStub(expected), nameof(activityIndicator.Background));
 		}
+
+#if WINDOWS
+		[Theory(DisplayName = "Foreground Updates Correctly")]
+		[InlineData(0xFFFF0000)]
+		[InlineData(0xFF00FF00)]
+		[InlineData(0xFF0000FF)]
+		public async Task ForegroundUpdatesCorrectly(uint color)
+		{
+			var expected = Color.FromUint(color);
+
+			var activityIndicator = new ActivityIndicatorStub()
+			{
+				Color = Color.FromUint(0xFF888888),
+				IsRunning = true
+			};
+
+			await ValidateHasColor(activityIndicator, expected, () => activityIndicator.Color = expected, nameof(activityIndicator.Color));
+		}
+#endif
 	}
-}
+}